OF THE MOSSES AND THEIR ALLIES. 153 



between the sheets of paper, are saved from the wear and 

 tear to which they would be subjected if constantly brought 

 out for investigation. 



I am of opinion, that if the specimens were mounted in 

 silicate" of potash (or waterglass, as it is sometimes called), 

 much future time and trouble would be saved, as the leaf 

 would probably retain its fair appearance without being 

 immersed in water every time it was wanted. But my 

 own experience is not sufficient to justify me in recom- 

 mending it to others. [I have frequently employed silicate 

 'of potash as a preservative medium for the leaves of 

 Mosses and other objects. In some instances it has suc- 

 ceeded thoroughly, the leaflets retaining their fresh appear- 

 ance, and remaining unaltered. But it appears to be un- 

 certain in its action, ' vacuoles ' and bubbles often appear- 

 ing in its midst in the most unaccountable manner. For 

 pleasantness in using, rapidity in drying, &c, it surpasses 

 any mediiun with which I am acquainted. — Ed.] 



